Analysis On The Clinicopathology And Family History For Primary Esophageal Adenocarcinoma (EAC) In High-and-low Incidence Areas For EAC Over The Past Thirty Years(1981-2010)

1Background and PurposeEsophageal cancer (EC) is one of the six most common malignant diseases worldwide. EC has a striking geographical distribution that its morbidity and mortality can be difference above500times between the high and low-incidence areas of it. Esophageal cancer has two major histology types that were esophageal adenocarcinoma (EAC) and esophageal squamous cell carcinoma (ESCC). EAC is common esophagus malignant tumors in western country, which approximately accounts for80%in esophageal malignancies. In recent decades, the incidence of EAC in Western countries was rising persistently. In some developed countries, the EAC has been more than ESCC and become the most common esophageal cancer. In western countries, the researches for EAC that included epidemiology, clinical pathology, and molecular genetics were very extensively. Gastroesophageal reflux disease, obesity, smoking, drinking and some other factors were considered to be risk factors correlatively with the incidence of EAC.China has the highest incidence and mortality of esophageal cancer in the world. About160/100,000new patients with esophageal cancer in the world each year, however half of them were in China. In contrast with western countries, the majority of esophageal cancers were ESCC in China, and the proportion of EAC is very small. The small amounts of reports about EAC in China usually have limited sample size, and there were no epidemiological reports which had large sample size. In these literatures, we found that the clinical pathology and epidemiological characteristics of EAC were quite different from western countries’. It was noteworthy that the sample size for EAC was usually too small to make a reliable conclusion. So, to analyze the clinical pathological and epidemiological characteristics of the EAC and the change trend during the past several decades with large sample size is an urgent problem in China.882EAC patients’data were come from the databases of Henan Key Laboratory for Esophageal Cancer Research that enrolled by home/hospital questionnaire and telephone follow-up during30years which from1981to2010. Thus, our study discussed the relationships between the clinicopathological features and family history of EAC in China esophageal cancer high-incidence areas and the survival of these patients, as well as analyzed the change trend during the past30years through the data analyze of large sample size, and then deepened the cognition for the clinical pathological and epidemiological characteristics of the EAC.2Materials and MethodsAll the882patients diagnosed with EAC from1981to2010from the database of Henan Key Laboratory for Esophageal Cancer Research in this study. There are637patients with pure adenocarcinoma,8patients with adenoid cystic carcinoma,11patients with mucoepidermoid carcinoma and222patients with adenosquamous carcinoma (adeno-acanthoma). There were658males and224females; the sex ratio is3:1.19to91years old, with the mean age of61±10years. The clinicopathological data include name, gender, onset age, ethnicity, address, contact details, treatment time, treatment hospital, family history of cancer, tumor location, tumor differentiation, tumor gross type, TNM staging, survival, and so on. All the patients were confirmed the diagnosis as EAC by pathology. The clinical pathology information was collected by face-to-face epidemiological questionnaire surveys with patients in hospital or the patient’s home. We improved the relevant information from the medical record of hospitals where the patients were diagnosed and treated. A follow-up study by telephone was carried on and the information was collected. The last follow-up time was2012-3-22, follow-up rate was53.4%. The data was analyzed by SPSS19.0. Chi-square test was applied for data analysis, using the Kaplan-Meier survival analysis and Log Rank test to assess the prognosis, the inspection level a=0.05. This study was approved by each institutional and hospital ethical committee and conducted according to Declaration of Helsinki principles.3Results3.1The distribution of clinical and pathological features3.1.1The distribution of general condition for EACEAC occurred predominantly in male (male:female=2.9:1),50-60years old was the peak ages (69%); the proportion was approximation in the high and low incidence(52%and48%); rural population slightly higher than the urban population (55%＞45%); the rate of positive family history was26%.3.1.2The distribution of pathological features for EACEAC occurred more frequently in middle (49%) and lower (46%) segment of esophagus; grossly, ulcer type was the most common (54%), then the medullary type (19%); poor differentiation (59%) was more frequently observed, followed by middle (33%); more than95%patients were middle or late stage in the first diagnosis, almost half of the EAC patients were diagnosed with lymph node metastasis (48%).3.2The change of clinicopathological features for EAC in three10-yearsBased on diagnosed time, the patients were divided into early (1981-1990), middle (1991-2000) and latest (2001-2010) with each period of three10-years. Comparative analysis for these three periods showed that the detection rate of EAC in the lower segment of esophagus emerged a declining tendency (75%vs.43%and44%,X2=17.876, P<0.05) during the past30years, and the similar results were observed for lymph node metastasis (56%vs.56%and43%,X2=7.565, P<0.05). In contrast, the early EAC demonstrated an increasing tendency (3%vs.4%and5%, X2=12.266, P<0.05), and the similar results for the incidence of EAC in the low-incidence areas (28%vs.25%and62%,X2=74.635, P＜0.05) and so in rural (11% vs.35%and75%,X2=127.888, P＜0.05).3.3The survival analysis for EACThe5-year survival rate of EAC was20%in three10-years. The key risk factor was lymph node metastasis. The median survival time of Lymph node metastasis-positive and-negative patients was30and112month (X2=14.539, P＜0.05). Smoking history was the independent risk factors for male in the gender-stratified analysis. The median survival time of smoking history-positive and-negative patients was32and51month (X2=5.094, P＜0.05).T stage of the TNM and the distribution in urban or rural were the independent risk factors for low incidence areas in the stratified analysis with high-and-low incidence areas. The median survival time of T1and T4was68and8month (X2=10.686, P＜0.05). The median survival time of urban and rural in low incidence areas was30and68month (X2=4.050, P＜0.05).4Conclusions4.1The incidence of EAC in china, especially the old patients is upward trend over the past30years, but IT IS still in the minority of esophageal cancer. EAC usually occurs in the middle and lower segments of the esophagus with poorly differentiated, ulcer type, and advanced stage; lymph node metastasis is frequently observed.4.2The composition ratio of EAC patients in the high-incidence areas is similar as in the low-incidence areas, suggesting that the geographic distribution of EAC may be different from ESCC. Approximately30%of the EAC patients have positive family history, suggesting that genetic factor may play a role in the pathogenesis of EAC.4.3The5-year survival rate OF EAC was20%. Lymph node metastasis is the independent risk factors.